Spring Boot 容器选择 Undertow 而不是 Tomcat

Spring Boot内嵌容器支持Tomcat、Jetty、Undertow。为什么选择Undertow？

这里有一篇文章，时间 2017年1月26日发布的：
Tomcat vs. Jetty vs. Undertow: Comparison of Spring Boot Embedded Servlet Containers
这篇文章详细测试了Spring Boot应用在三种容器下的性能和内存使用，内含完整的测试代码和测试流程。证明了Undertow在性能和内存使用上是最好的。

在Spring Boot中使用 Undertow 而不是 Tomcat

1、Maven示例：

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-web</artifactId>    <exclusions>        <exclusion>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-tomcat</artifactId>        </exclusion>    </exclusions></dependency><dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-undertow</artifactId></dependency>

2、配置Undertow，application.yml示例：

server.undertow.accesslog.dir= # Undertow access log directory.server.undertow.accesslog.enabled=false # Enable access log.server.undertow.accesslog.pattern=common # Format pattern for access logs.server.undertow.accesslog.prefix=access_log. # Log file name prefix.server.undertow.accesslog.rotate=true # Enable access log rotation.server.undertow.accesslog.suffix=log # Log file name suffix.server.undertow.buffer-size= # Size of each buffer in bytes.server.undertow.buffers-per-region= # Number of buffer per region.server.undertow.direct-buffers= # Allocate buffers outside the Java heap.server.undertow.io-threads= # Number of I/O threads to create for the worker.server.undertow.max-http-post-size=0 # Maximum size in bytes of the HTTP post content.server.undertow.worker-threads= # Number of worker threads.

3、使用 Undertow 监听多个端口示例：

@Beanpublic UndertowEmbeddedServletContainerFactory embeddedServletContainerFactory() {    UndertowEmbeddedServletContainerFactory factory = new UndertowEmbeddedServletContainerFactory();    factory.addBuilderCustomizers(new UndertowBuilderCustomizer() {        @Override        public void customize(Builder builder) {            builder.addHttpListener(8080, "0.0.0.0");        }    });    return factory;}